Jimmy Vaccaro, the 71-year-old doyen of Las Vegas oddsmakers, says that in the last week only five to 10 people have come to his counter at the South Point Casino's Sports Book lounge to ask him about the presidential election. "Used to be five to 10 people every two hours," Vaccaro says. "The interest is waning. We're worn out here."

Yet in Nevada, a state that has called every presidential race in the last 60 years (except in 1976, when it favored Gerald Ford over Jimmy Carter), the contest is too close to call.

Vaccaro's odds have been "for entertainment purposes only," a mere publicity instrument for the casino where he works. Politics is one of the few sports on which the Nevada gaming industry cannot take bets. He and other bookies here, as well as at least one state senator, believe the state missed a golden opportunity this year by not allowing betting on what Vaccaro calls "the most cantankerous election in history."

Swing State

Like many other U.S. states, Nevada should be leaning Democratic this election cycle because of major demographic changes. According to an analysis by Project New America, a Colorado-based company that advises various progressive organizations, the state added almost 81,000 non-white registered voters this year, accounting for a third of all new registrations. Almost 48,000 of these are Hispanic, a group that this year is mostly expected to vote for the Democratic ticket. Out of 1.5 million registered voters, more than 500,000 are millennials -- a sharp increase from last year.

Besides, unlike in 2014, when Republicans swept the state -- winning the governorship, a legislative majority and three of the state's four seats in the U.S. House -- the Democrats are making a much bigger effort this year. In 2014, very few young people and non-white voters turned out. According to Michael Green, a historian at the University of Nevada, that was in part because the state's most powerful get-out-the-vote machine -- the Culinary Workers Union, which represents the staff of hotels and casinos -- had "gone on vacation."

"They were upset about certain aspects of Obamacare and the failure of the immigration reform, so they decided to send the Democrats a message," Green says. "Well, they got that message themselves, too, so they're all in this year."

David Damore, a University of Nevada political scientist, says Donald Trump has mobilized Hispanic voters against him this year: They are more likely to turn out than in 2014 because of his controversial stance on immigrants. They also have a chance to send the first Latina to the U.S. Senate: Catherine Cortez Masto, the chosen successor of Minority leader Harry Reid, a prominent figure in Nevada politics, is running for the seat he has vacated.

The Democrats have a good chance of winning back the legislature and two U.S. Congress seats: Nevada's Republicans are in disarray, receiving, according to Damore, only a third of the transfers that the state Democrats are getting from the national party.

And yet the most recent polls show that all the Nevada races -- for president, the U.S. Senate and U.S. House -- are all too close to call. Nevada, Damore says, has a small-state culture of personalized politics -- but that doesn't always decide its important elections. As a swing state, Nevada is inundated with outside money from powerful donors such as the Koch brothers, meaning that local candidates don't fully control their message. Besides, relatively few Nevada voters were born in the state. In-migration has made Nevada a microcosm of U.S. demographics shifts.

"We are not trend-setters," Green says. "We don't swing national election outcomes, we swing with the country."

Unreliable Polls

Using Nevada as a bellwether of how the country will swing is tricky, however. "The polls are garbage here," Damore says. He suspects the pollsters don't speak enough Spanish to cover the growing Hispanic population. There could be other factors skewing the polls, though: Nevada's constantly churning, unrooted population is not politically active. In 2014, only 29 percent of eligible voters cast a ballot, one of the lowest participation rates in the U.S. Of the 1.5 million registered voters -- a relatively small share of the eligible population -- more than 260,000 are listed as inactive, meaning they have moved out of the county where they were registered.

It's difficult to capture the preferences of such a fluid and relatively disinterested electorate amid rapid demographic change; Nevada is just a rather extreme illustration of the problems pollsters face throughout the U.S. Like their U.K. counterparts during the recent general election and European Union referendum, they may discover that their techniques and models failed to reflect a highly unusual election.

Oddsmaker Jimmy Vaccaro at his counter

Photographer: Leonid Bershidsky

Vaccaro doesn't put much stock in the polls, either: He says oddsmaking is an art, not a science.

"CNN has a poll that favors Hillary and Fox has a poll that favors Trump -- everybody's got a poll," he says. "It's like you tell me,' Jimmy boy, how can you make it 3-to-1 when it should be seven?' I'm going to let you say your piece, but I'm going to put up the number that I think is right."

According to Vaccaro, Paddy Power, the Ireland-based sports betting giant, has a representative in the U.S. whose job is to follow every twist and turn of the election and report to head office so they can adjust the odds. That kind of approach may not have the academic veneer of polling, but Damore, for one, would be happy for the additional input. "It would help me see through the bad polling," he says.

Since the primaries, I have been corresponding with Robert Barnes, a Las Vegas lawyer who, as a sideline, consults people on political wagering and makes big bets on elections on his own account in the U.K. He was betting heavily on Trump long before it was clear that he would be the Republican nominee. He also advised his clients to put their money on an "Out" vote in the U.K.'s European Union referendum. Both bets paid off handsomely.

Barnes says he has no use for the official polls because he believes they give disproportionate weight to more educated and affluent voters. He's betting on Trump to win the election. Vaccaro, who has cast an early vote for Trump ("It's mostly a vote against her," he says), considers Clinton a 6-to-1 favorite to win. Yet he adds, "That doesn't mean Trump can't win. I've seen a million six-to-one shots. In betting, nothing is absolute."

Outdated Ban

Paddy Power's odds are 5-to-1 on Clinton and 1-to-4 on Trump. Americans, however, can't bet: Global betting companies are gearing up for the broader legalization of sports wagering in the U.S., and they are careful not to do anything U.S. regulators might consider illegal. To make a wager on the U.S. election at a trustworthy venue, a U.S. citizen must travel overseas, pay the bookmaker in cash and hope his ID is not checked. Barnes travels to London with his money; most of the clients he consults are European residents, he says, so they don't have the same problem.

To Vaccaro, this is painfully unfair. "Nobody cares who's going to be the next king of Spain or the next king of Peru," he says. "We're the only country in the world where everybody's watching the election very closely. In England, it's probably the second biggest book after their Premier League games."

Barnes says he and his clients collectively have a seven-figure amount riding on Trump's success. Yet most of the tens of millions of dollars that are being bet on the U.S. election in Europe and the Caribbean is put up by people with little understanding of the intricacies of U.S. politics. If U.S. casinos were able to make book and better-informed U.S. gamblers kept them on their toes, the odds would probably be different than in Europe -- and more useful to people building composite forecasting models that rely on various inputs such as polls, data from bookmakers and social networks.

It could also be a boon for Nevada, where gaming is the No. 1 industry. Three years ago, State Senator Richard "Tick" Segerblom introduced a bill that would allow political betting, but it ultimately died. "It seemed like a no-brainer," Segerblom told me. "But they said it would be bad for Nevada's reputation. Come on guys, this is Nevada's reputation."

Another argument Segerblom heard was that political betting could result in politicians intentionally throwing elections. It's hard to imagine anyone would do so in a presidential race, with more at stake than any amount of money can buy. And even if someone decided to run such a scam, the casinos probably would catch them as they regularly do with sports betting, Segerblom said.

People I talked to in Las Vegas struggled to explain the ban.

"Old-timers are still in power, the ones you can't change who just don't like it," Vaccaro said. "It's the idea of gambling and the idea of bookmakers -- it's like they always have black clouds over their heads."

Green, the historian, told me he had been unable to discover the origins of the ban on political betting. "Few people think of Nevada as hypocritical, but it can be," he said. "We are the only state that allows prostitution, but we don't allow political betting."

If the ban were lifted, a sizable market would spring up overnight. "It would be the most popular wager we would accept, including the Super Bowl," Jay Kornegay, a vice president at the Westgate Las Vegas Superbook, told me in an e-mail.

Vaccaro also believes the presidential election could surpass the Super Bowl's $132 million in bets. He says if the rest of the country and perhaps the world were allowed to bet on the U.S. election at the Vegas casinos, the figure could run into the billions.

"These are the most trusted casinos in the world," Barnes said as we sat at the Wynn Sports Book. "Bans only drive betting underground."

It's easy for me, a resident of Germany, to place a bet on the U.S. election, but the contest is stressful enough to watch even if you don't have skin in the game. Nevada's voters, however, may need a financial incentive to come to the polls in greater numbers. "If you can bet on it, you definitely go out and vote," Vaccaro said.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.